Atmospheric burner unit for unvented gas logs heater

ABSTRACT

An atmospheric burner unit for use in an unvented gas log heater has a base and a gas distribution valve supported by the base. The valve has an inlet opening and a number of outlet openings. A plurality of burner elements are mounted by the base. Each of the burner elements has an inlet port and a plurality of outlet ports. The inlet port of each burner element is in proximate spaced relationship with an outlet opening of the gas distribution valve thereby defining open spaces through which gas may flow from the distribution valve to the burner elements thus obviating the use of tubes or other conduits.

[0001] This application is based on provisional application 60/374,968,filed Apr. 23, 2002.

[0002] The present invention relates to gas burners. More particularly,the present invention relates to an atmospheric gas burner unit for usein an unvented, gas log heater.

BACKGROUND OF THE INVENTION

[0003] Unvented gas log units are popular products for supplementalheating and decorative use in residential housing and commercialestablishments in the United States and other countries. Manufacturersoffer many different models to appeal to consumers' tastes.Differentiation is generally achieved through artificial log appearance,grate design, flame color and control system.

[0004] The artificial logs attempt to duplicate the appearance of wood,such as oak or birch, for example, a cut (round or split) and other woodfeatures such as knotholes, peeled bark or branching. These artificiallogs are typically made of refractory ceramic fiber or concretecomposite.

[0005] The grate may be straightforward or ornate in design. Cast iron,sheet metal and brass are typical materials used to make these grates.

[0006] The atmospheric gas burners provide either blue or yellow flames.On most manufacturers' designs, blue flame burners are used inconjunction with refractory ceramic logs to create glowing surfaces thatradiate heat. Yellow flame burners can be used with any artificial logmaterial as the flames should not touch any log surface in order toensure low emissions (e.g., less than 0.02% air-free carbon monoxide)and to prevent possible soot generation.

[0007] The control systems can have manual, thermostat, wireless remoteor wired remote operation. The control systems also include pilot- flameignition units and safety control valves.

[0008] The national product standard, ANZI Z21.11.2, regulates themaximum allowable input of unvented gas logs to 40,000 BTU/hour. Manyprior art gas log units have only one burner; consequently, the minimumheat input that can be achieved would be about 20,000 BTU/hour. As asupplemental heater, this amount of heat is too much for mostapplications.

[0009] Several advantages exist with gas log units having multipleburners that are smaller in size and input. First, each burner by itselfhas a low-heat input. As an example, an invented gas log unit may havefive burners of 7,000 BTU/hour each. Any number can be turned “on”thereby producing a wide-range of total input. In this example, theinput settings could be 7,000 to 35,000 BTU/hour on 7,000 BTU/hourincrements. These variable inputs would satisfy the supplemental heatingrequirements for a room under any operating parameters (such as volumeof space, outside temperature, air exchange rate and desired insidetemperature, for example). Second, these burners would be operatedeither full “on” or “off ” This all-or-nothing mode results in the bestcombustion characteristics and eliminates the emissions problemsassociated with modulation, Importantly, modulation is a significantconsideration relative to low nitrogen dioxide (NO2) designs—a pendingrequirement in this product category. Third, different burners can bearranged to achieve a multiplicity of aesthetic appearances, such ashorizontal ember beds, vertical radiant surfaces, blue flames, yellowflames, yellow/blue flames for example.

[0010] Unfortunately, there are disadvantages associated with the priorart multiple burner units. The provision of multiple burners necessarilyrequires a substantial amount of tubing to direct the gas (natural gasor liquefied petroleum, commonly known as propane or LP), from thesource to the various burners. Of course, this necessary tubingincreases the costs of material and assembly labor.

[0011] Representative prior art patents are: Smith U.S. Pat. Nos.5,470,018; Manning et al 5,795,145; and Manning et al 5,915,952.

SUMMARY AND OBJECTS OF THE INVENTION

[0012] The invention resides in an atmospheric burner unit for a gas logheater having a unique gas distribution valve associated with multipleburners in a manner which minimizes the amount of tubing required todirect the gas to the various burners.

[0013] A primary object of the present invention is the provision of anatmospheric burner unit wherein gas may be directed from plural outletson the distribution valve to multiple burners without the need fortubing.

[0014] Another object of the present invention is the provision of anatmospheric burner unit wherein multiple burners may be ignited directlyor indirectly from a single ignition unit.

[0015] These and other objects and advantages of the present inventionmay be ascertained from the following description and drawings of apreferred embodiment.

DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is an isometric view of an unvented artificial gas logfireplace assembly embodying the atmospheric burner unit of the presentinvention;

[0017]FIG. 2 is an exploded isometric view of the artificial gas logfireplace assembly embodying the atmospheric burner unit of the presentinvention;

[0018]FIG. 3 is a top view of the atmospheric burner unit of the presentinvention;

[0019]FIG. 4 is a section taken generally along the line 4-4 of FIG. 3;

[0020]FIG. 5 is an enlarged, fragmentary, isometric top view;

[0021]FIG. 6 is an enlarged, fragmentary bottom view of the burner unit;

[0022]FIG. 7 is an enlarged, fragmentary bottom view showing primarilythe gas distribution valve;

[0023]FIG. 8 is a side view of the gas distribution valve;

[0024]FIG. 9 is a top view of the gas distribution valve;

[0025]FIG. 10 is a rear view of the distribution valve;

[0026]FIG. 11 is a diagrammatic view showing operation of thedistribution valve; and.

[0027] FIGS. 12A-12F are schematic views shoeing operation of thedistribution valve.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0028] Referring first to FIGS. 1 and 2, an unvented gas log fireplaceassembly is generally designated 2. This assembly includes artificiallogs 3, 4, 5, 6 and 7. As indicated above, these logs are typically madeof refactory ceramic fiber or a concrete composite. The gas log heaterassembly 2 also includes an atmospheric burner unit, generallydesignated 10, which embodies the present invention. Of course, theartificial logs may be provided in a variety of sizes and shapes asdesired. Suitable brackets and stands (not shown) may be provided tosupport the logs on and above the burner unit.

[0029] Now referring primarily to FIGS. 3, 4 and 5, the atmospheric gasburner unit 10 includes a stamped sheet metal frame or base defined bywalls 12 through 22. A front wall 23 having a flange 24 may be suitablyattached to the sheet metal section forming the walls 12 through 22.

[0030] It will be noted that the walls 16, 17 and 18 form a recess orcavity for receiving a gas distribution valve, generally designated 25.(This valve is disclosed to some extent in Italian applicationM02000A000241, filed Nov. 3, 2000, and assigned to the assignee of thepresent application).

[0031] Referring to FIGS. 8, and 9 it will be noted that the valve 25has a cylindrical outlet 26 with an exterior threaded portion receivedwithin an opening (not shown) in the wall section 17. A fastener 27(FIG. 5) is engaged with the threaded formation on the outlet 26 forsecuring the distribution valve 25 to the base frame.

[0032] Still referring to FIG. 5, it will be seen that the fastener 27also engages an elbow 28. This elbow is connected to a tube 30 by meansof a fastener 32. The tube 30 is attached to, and communicates with theinterior of, a tube burner generally designated 34. The opening (notshown) in the burner 34 which communicates with the tube 30 serves asthe gas inlet port for the tube burner 34.

[0033] The tube burner 34 may be of a variety of shapes depending on thedesired configuration of the logs. In the embodiment shown for purposesof illustration, the tube burner 34 has four rectilinear sectionsprovided with respective sets of outlet ports 36, 38, 39 and 40. Thetube burner 34 is also provided with end caps 42 and 43 as best seen inFIG. 4.

[0034] The tube burner 34 is suitably mounted to the base frame. Thistube burner is preferably, but not necessarily, adapted to produceyellow flames.

[0035] The atmospheric gas burner unit 10 also includes four bladeburners 50, 51, 52 and 53, These blade burners may be adapted to produceblue or yellow flames or a mixture thereof The four blade burners are ofidentical construction.

[0036] Referring to FIG. 7, each blade burner includes a central openingor chamber 55 having a flared inlet portion 55 a at its inner end. Eachblade burner has a set of outlet openings or ports 56 communicating withthe chamber 55.

[0037] Referring particularly to FIGS. 8, 9 and 10, the gas distributionvalve 25 includes an inlet opening 60 and six outlet openings includingthe outlet opening 26 and five additional outlet openings 62-66, Theoutlet 26 communicates with the elbow 28 for delivering gas to the tubeburner 34. The outlet 62 communicates with the flared opening 55 a ofthe blade burner 52. Similarly, the outlet 63 communicates with theopening 55 in the blade burner 51. The outlet 64 communicates with thechamber 55 of the blade burner 50; the outlet opening 65 communicateswith the opening 55 in the blade burner 53. Finally, the outlet opening66 communicates with a tube 70 (FIGS. 6 and 7) extending to a pilotlight and ignition assembly 72 shown in FIG. 6. As noted in FIG. 7, eachof the outlet openings 62-65 preferably communicate with an outletnipple, such as the nipple 76, to facilitate the passage of gas to theadjacent flared openings 55 a in the respective blade burners.

[0038] As seen in FIG. 6, the inlet opening 60 communicates with a tube74 extending to a thermostat and safety control valve, generallydesignated 75. This control valve communicates with the main regulatorassembly (not shown).

[0039] The gas distribution valve 25 has a central longitudinal bore 80(FIGS. 12A-12) rotatably receiving a cylindrical valve member 82 whichis attached to the valve stem 78. An operating knob (not shown) may beattached to the valve stem for manually rotating the cylindrical valvemember to the desired rotary position. It will be understood that thecyclindrical valve member 82 has various passageways (shownschematically in FIGS. 12A-12F) for communicating the inlet opening 60with one or more of the valve outlet openings 26 and 62-66. This valvemember is similar to the valve shown in U.S. Pat. No. 5,470,018 referredto above.

[0040] Turning to FIGS. 11 12A-12F, when the rotary valve member 82 isin the “0” position, the inlet opening 60 is not in communication withany of the outlet openings. When the control knob is rotatedcounterclockwise (as seen in FIG. 11) to position “1”, the inlet opening60 is placed in communication with outlet 66 for admitting gas to thepilot light and ignition assembly 72. During successive rotation of thevalve member, the inlet opening 62 remains in communication with theoutlet opening 66 which extends to the pilot light assembly.

[0041] When the operating member is rotated to position “2” shown inFIG. 11, gas is admitted to outlet opening 26 thereby permitting theflow of gas to tube burner 34 for exit from the ports 36, 38, 39 and 40and ignition by the pilot light assembly 72. Movement of the cylindricalvalve member to position “3” shown in FIG. 11 permits the flow of gas tooutlets 66, 26 and 62, the latter communicating with right rear bladeburner 50. Gas in blade burner 50 is ignited from the flames emanatingfrom tube burner 34. As noted in FIG. 5, a set of transfer ports 80 inburner 34 facilitates the ignition of gas in blade burner 50.

[0042] When the rotary valve member is rotated to position “4” shown inFIG. 11, left rear blade burner 51 will receive the supply of gas; thisgas will be ignited from the flames emanating from the set of ports 36in tube burner 34, again through the agency of transfer ports (notshown) formed in the burner 34 adjacent the ports 36. Finally when therotary valve member is rotated to position “5” as seen in FIG. 11, bothfront blade burners 52 and 53 will receive the flow of gas. These twoburners will be ignited from blade burners 50 and 51 because of theclose proximity of the inner ends of burners 50,52 and thew inner endsof blade burners 51,53.

[0043] The present invention has been described in detail with referenceto a preferred embodiment thereof However, variations and modificationscan be effected within the spirit and scope of the invention as definedby the following claims.

We claim: 1) A gas burner assembly comprising: a) a base; b) a gasdistribution valve supported by the base and having an inlet opening anda plurality of outlet openings; and c) a plurality of burner elementsmounted by the base, each having an inlet port and a plurality of outletports, the inlet port of each burner element being in proximate spacedrelationship with respective ones of said valve outlet openings therebydefining open spaces through which gas may flow from the distributionvalve to the burner elements 2) A gas burner assembly comprising: a) abase; b) a gas distribution valve supported by the base and having aninlet opening and plurality of outlet openings; c) a first burnerelement mounted by the base and having an inlet port and a plurality ofoutlet ports; d) conduit means communicating said inlet port of thefirst burner element with one of the outlet openings of the distributionvalve; e) a plurality of second burner elements mounted by the base andeach having an inlet port and a plurality of outlet ports, the inletports of the second burner elements being in proximate spacedrelationship with respective other outlet openings of the gasdistribution valve thereby defining open spaces through which gas mayflow from the distribution valve to the second burner elements; and f)an ignition unit mounted by the base in adjacent relationship with oneof said first and second burner elements thereby to ignite gas admittedto said one of said first and second burner elements, at least one ofthe others of said first and second burner elements having a portionthereof in adjacent relationship with said one of said first and secondburner elements whereby gas ignition in said one of said first andsecond burner elements causes ignition in the others of said first andsecond burner elements. 3) A gas burner assembly comprising: a) a base;b) a gas distribution valve supported by the base and having an inletopening and a plurality of outlet openings; c) a plurality of burnerelements mounted by the base and each having an inlet port and aplurality of outlet ports, the inlet ports of the burner elements beingin proximate spaced relationship with respective outlet openings of thedistribution valve thereby to define open spaces through which gas mayflow from the valve outlet openings to the burner elements; and d) anignition unit mounted on the base in adjacent relationship with one ofsaid burner elements thereby to ignite gas admitted to said one burnerelement, at least one of the others of said burner elements having aportion thereof in adjacent relationship with said one burner elementwhereby gas ignition in said one burner element causes ignition in theothers, of said burner elements. 4) The gas burner assembly according toclaims 1, 2 or 3 wherein said distribution valve is further defined by:a) a valve body having a first cylindrical bore; b) said valve bodyhaving a plurality of second through bores each communicating with saidcylindrical bore and defining said outlet openings of the distributionvalve; c) a cylindrical valve unit mounted in said first cylindricalbore for rotation therein and having an axial bore defining at least inpart said inlet opening of the distribution valve, said cylindricalvalve unit also having a plurality of radial through bores eachcommunicating with said axial bore, said radial through bores beingpositioned for selective registry with respective ones of said secondthrough bores in response to rotary movement of said cylindrical valveunit. 5) The gas burner assembly according to claim 4 wherein at leastthree of said second through bores define longitudinal central axescontained in a common plane perpendicular to the axis of rotation ofsaid cylindrical valve unit. 6) The gas burner assembly according toclaim 2 wherein said ignition unit is mounted adjacent said first burnerelement.